Australasian Dentist Magazine March April 2021

Category Australasian Dentist 45 compared to BC30, for which there was no apparent growth inhibition even with the highest concentration of 8% (v/v). Discussion There is a need for novel antimicrobial agents with improved activity and safety profiles. A range of substances extracted from plants have shown promise in this respect. Peel extracts from Citrus sudachi have been found to have antimicrobial activity against bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and Helicobacter pylori. 23 Other bioactive plant extracts, containing flavonoids and phenols as major components, have proven effective against MRSA and a range of Gram-negative bacteria. 27,28 From the oral perspective, naringin, a flavonoid extract from grapefruit, has shown promise in the growth inhibition of A. actinomycetemcomitans and P. gingivalis in planktonic phase. 29 Polyphenols extracted from hop extracts and cranberry have shown activity against streptococcal species associated with dental caries 30-32 and a citrus extract combined with lemon juice and lemon grass has been used successfully to treat oral candidosis. 33 The results of the present study show for the first time the impact of a citrus fruit bioflavonoid based product (Citrox ® ) on the growth of a range of oral microorganisms. Both formulations of Citrox ® tested showed substantial antimicrobial activity, with BC30 exhibiting biofilm MIC values below 0.5% for all bacterial strains tested. Although the MIC values are not directly comparable, the antimicrobial activity and range compare favourably with those reported for chlorhexidine, an essential oil mouthwash and a herbal mouthwash containing grapefruit seed extract when tested against a similar range of oral bacteria. 34 In general the BC30 formulation demonstrated higher activity against both bacteria and yeasts. Interestingly, the two species of Candida demonstrating a high MIC with the BC30 preparation ( C. albicans and C. dubliniensis ) were significantly more susceptible to the MDC30 formulation. For these two species MDC30 demonstrated greater activity than that previously reported for chlorhexidine. 35 Citrox ® MDC contains the same bioflavonoids as BC30 but, in addition, incorporates citric acid and choline ascorbate. The antimicrobial activity of the bioflavonoid preparations when tested against bacterial and fungal biofilms is significant and of direct clinical relevance. Biofilms can be defined as microbial cells attached to a surface and organised into structured communities embedded clinical Fig. 2 Relative growth in biofilm of the 14 test strains in the presence of varying concentrations of Citrox®BC 30 and MDC 30